Suppose an example. I have following interface:
public interface DataSource<T> {
Future<T> fetch();
}
This datasource can do asynchronous data fetching. And we have following tag
for using datasource in JSP:
<html>
<d:fetch from="${orderDS}" var="orders">
<c:foreach in="${orders}" var="order">
<div class="order">
<c:out value="${order.title}" />
</div>
</c:foreach>
</d:fetch>
</html>
So, what I want? I want JSP rendering engine to
call my custom tag (FetchTag in this example) twice. On first
call FetchTag will do DataSource.fetch()
call and save Future locally as a object field. On second
call FetchTag do Future.get()
call and will be blocked until data becomes available.
Is there any way to do such a thing?
